Testing Device and Testing Method for Magnetic Permeability of Magnetic Devices

Abstract

The present invention provides a test device and a test method for the magnetic permeability of a magnetic device. The test device for magnetic permeability includes: a fixture for clamping the magnetic device, where the magnetic device includes a magnetic ring through which a single-turn coil passes; a measuring instrument for measuring the insertion loss or S21 parameter of the magnetic device; and a host computer connected to the measuring instrument for receiving the insertion loss or S21 parameter, calculating the magnetic permeability using the insertion loss and the conversion formula between the insertion loss and the magnetic permeability for a single-turn coil, or calculating the magnetic permeability using the S21 parameter and the conversion formula between the S21 parameter and the magnetic permeability for a single-turn coil. The test device and test method for the magnetic permeability of the magnetic device of the present invention can simply and conveniently test the magnetic permeability and reduce the test cost.

Description

Technical Field

[0001] The present invention mainly relates to the field of electromagnetic compatibility testing, and particularly to a testing device and method for the magnetic permeability of magnetic devices. Background Art

[0002] Magnetic devices are very important devices for energy storage and energy conversion in circuits. There are many parameters to describe the characteristics of magnetic devices. Among them, magnetic permeability is one of the most important characteristic parameters. Magnetic permeability is further divided into initial magnetic permeability, maximum magnetic permeability, and saturation magnetic permeability. Although magnetic permeability has such classifications, in essence, they are different names for magnetic permeability under different loading conditions and frequencies.

[0003] In some applications, such as the field of electromagnetic compatibility, as a filtering device, the curve of the magnetic permeability of a magnetic device changing with frequency is a very important curve. However, the current methods for testing magnetic permeability are very complex and rely on expensive impedance analyzers or other instruments for testing. Therefore, there is an urgent need in the field for a method that can more conveniently test magnetic permeability. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a testing device and method for the magnetic permeability of magnetic devices, which can simply and conveniently test magnetic permeability and reduce the testing cost.

[0005] To solve the above technical problem, the present invention provides a testing device for the magnetic permeability of magnetic devices, including: a fixture for clamping a magnetic device, where the magnetic device includes a magnetic ring penetrated by a single-turn coil; a measuring instrument for measuring the insertion loss or S21 parameter of the magnetic device; and a host computer connected to the measuring instrument for receiving the insertion loss or S21 parameter, using the insertion loss and calculating the magnetic permeability according to the conversion formula between the insertion loss and magnetic permeability in the case of a single-turn coil, or using the S21 parameter and calculating the magnetic permeability according to the conversion formula between the S21 parameter and magnetic permeability in the case of a single-turn coil.

[0006] In an embodiment of the present invention, the conversion formula between the insertion loss and magnetic permeability in the case of a single-turn coil is:

[0007]

[0008] Or:

[0009]

[0010] Where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and IL is the insertion loss.

[0011] In an embodiment of the present invention, the conversion formula between the S21 parameter of the single-turn coil and the magnetic permeability is:

[0012]

[0013] Or:

[0014]

[0015] Where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and S21 is the S21 parameter.

[0016] In an embodiment of the present invention, the fixture includes a base, a column provided on the base and for passing through the magnetic ring, and a connection end located on the outer surface of the base.

[0017] To solve the above technical problems, the present invention also provides a method for testing the magnetic permeability of a magnetic device, including the following steps: clamping the magnetic device, the magnetic device including a magnetic ring through which a single-turn coil passes; measuring the insertion loss or S21 parameter of the magnetic device; and calculating the magnetic permeability using the insertion loss according to the conversion formula between the insertion loss and the magnetic permeability of the single-turn coil, or calculating the magnetic permeability using the S21 parameter according to the conversion formula between the S21 parameter and the magnetic permeability of the single-turn coil.

[0018] In an embodiment of the testing method of the present invention, the conversion formula between the insertion loss and the magnetic permeability of the single-turn coil is:

[0019]

[0020] Or:

[0021]

[0022] Where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and IL is the insertion loss.

[0023] In an embodiment of the testing method of the present invention, the conversion formula between the S21 parameter and the magnetic permeability of the single-turn coil is:

[0024]

[0025] Or:

[0026]

[0027] Where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and S21 is the S21 parameter.

[0028] Compared with the prior art, the present invention has the following advantages: The test device and test method for the magnetic permeability of the magnetic device of the present invention utilize the insertion loss device or the test means of the S21 parameter. After testing the insertion loss or the S21 parameter of the magnetic device through software calculation and parameter extraction, the magnetic permeability / frequency curve can be directly obtained. The test method is very simple, effectively reducing the test cost. Description of the Drawings

[0029] The included drawings are provided to provide a further understanding of the present application. They are incorporated and constitute a part of the present application. The drawings illustrate the embodiments of the present application and, together with this specification, serve to explain the principles of the present invention. In the drawings:

[0030] Figure 1 is a schematic diagram of a test device for the magnetic permeability of a magnetic device according to an embodiment of the present invention;

[0031] Figure 2a is a schematic diagram of a test device for the magnetic permeability of a magnetic device with an insertion loss tester according to an embodiment of the present invention;

[0032] Figure 2b is a schematic diagram of a test device for the magnetic permeability of a magnetic device with a network analyzer according to an embodiment of the present invention;

[0033] Figure 3a is a schematic diagram of the structure of a fixture in a test device for the magnetic permeability of a magnetic device according to an embodiment of the present invention;

[0034] Figure 3b is a schematic diagram of the structure of a fixture in a test device for the magnetic permeability of a magnetic device according to another embodiment of the present invention; and

[0035] Figure 4 is a schematic diagram of the flow of a test method for the magnetic permeability of a magnetic device according to an embodiment of the present invention.

[0036] Figures 1 to 3b List of reference signs in

[0037] 10 Test device for the magnetic permeability of a magnetic device

[0038] 11 Fixture

[0039] 12 Measuring instrument

[0040] 13 Host computer

[0041] 21 Testing device for magnetic permeability of magnetic devices with insertion loss tester

[0042] 212 Insertion loss tester

[0043] 22 Testing device for magnetic permeability of magnetic devices with network analyzer

[0044] 222 Network analyzer

[0045] 110 Base

[0046] 111 Cylinder

[0047] 112 Connection end

[0048] a Magnetic ring Detailed implementation manners

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the figures represent the same structure or operation.

[0050] As shown in the present application and the claims, unless the context clearly indicates an exception, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0051] Unless otherwise specifically stated, the relative arrangements of the components and steps described in these embodiments, numerical expressions and values do not limit the scope of the present application. At the same time, it should be understood that for the convenience of description, the dimensions of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant fields may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0052] In the description of the present application, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description. Without contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present application; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0053] For convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above-mentioned", etc. can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to cover different orientations in use or operation in addition to the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0054] In addition, it should be noted that the use of words such as "first", "second", etc. to limit components is only for the convenience of distinguishing the corresponding components. Without separate declaration, the above words have no special meaning. Therefore, it should not be construed as a limitation on the protection scope of the present application. In addition, although the terms used in the present application are selected from well-known and commonly used terms, some of the terms mentioned in the specification of the present application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of the description herein. In addition, it is required to understand the present application not only through the actual terms used, but also through the meaning implied by each term.

[0055] It should be understood that when a component is referred to as "on another component", "connected to another component", "coupled to another component", or "in contact with another component", it can be directly on, connected to, or coupled to, or in contact with the other component, or there may be an intervening component. In contrast, when a component is referred to as "directly on another component", "directly connected to", "directly coupled to", or "directly in contact with" another component, there is no intervening component. Similarly, when a first component is referred to as "electrically in contact with" or "electrically coupled to" a second component, there is an electrical path for current flow between the first component and the second component. The electrical path may include capacitors, coupled inductors, and / or other components that allow current flow, even if there is no direct contact between the conductive components.

[0056] An embodiment of the present invention provides a test device for the magnetic permeability of a magnetic device, which can simply and conveniently test the magnetic permeability and reduce the test cost.

[0057] As Figure 1 shown, it is a schematic diagram of a test device 10 for the magnetic permeability of a magnetic device according to an embodiment of the present invention. Among them, the test device 10 includes a fixture 11, a measuring instrument 12, and a host computer 13.

[0058] Specifically, the fixture 11 is used to clamp the magnetic device. In the embodiment of the present invention as Figure 1 shown, the magnetic device is a magnetic ring penetrated by a single-turn coil.

[0059] The host computer 13 is connected to the measuring instrument 12, and is used to receive the insertion loss or S21 parameter, and calculate the magnetic permeability using the conversion formula between the insertion loss and the magnetic permeability when using a single-turn coil, or calculate the magnetic permeability using the conversion formula between the S21 parameter and the magnetic permeability when using a single-turn coil.

[0060] Furthermore, in different embodiments of the present invention, the measuring instrument 12 can be a measuring instrument for measuring the insertion loss of the magnetic device, or a measuring instrument for testing the S21 parameter of the magnetic device. Thus, when the test device 10 uses different measuring instruments 12, the above-mentioned host computer 13 can respectively receive the insertion loss or S21 parameter, and calculate the magnetic permeability using the corresponding formula with the insertion loss or S21 parameter.

[0061] As Figure 2a shown, it is a schematic diagram of a test device 21 for the magnetic permeability of a magnetic device with an insertion loss test tooling according to an embodiment of the present invention. As Figure 2a shown in the embodiment can be as Figure 1A special case of the test device 10 shown. Therefore, the same parts in the test device 10 and the test device 21 are labeled with the same reference numerals, but the present invention is not limited thereto. In other embodiments of the present invention, the host computer and the fixture in the test device 21 may be different from those in the embodiment as shown in Figure 1 the embodiment shown.

[0062] In the test device 21 as shown in Figure 2a the measurement instrument 12 as shown in Figure 1 is specifically set as an insertion loss tester 212. The tracking source connection terminal TG and the RF signal connection terminal RF of the insertion loss tester 212 are respectively connected to both sides of the fixture 11, and the insertion loss tester 212 is also connected to the host computer 13. The host computer 13 can thus receive the insertion loss from the insertion loss tester 212, and then calculate the magnetic permeability according to the conversion formula between the insertion loss and the magnetic permeability for a single-turn coil.

[0063] Exemplarily, in an embodiment of the present invention, the conversion formula between the insertion loss and the magnetic permeability for a single-turn coil is:

[0064]

[0065] Or:

[0066]

[0067] where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and IL is the insertion loss. Which of the above two different formulas to apply is determined according to different parameters of the magnetic ring that can be obtained in different application scenarios. For example, in some cases, the effective cross-sectional area Ae and the magnetic path length le of the magnetic ring can be easily obtained from the parameter table of the magnetic ring. In this case, the formula involving the effective cross-sectional area Ae and the magnetic path length le can be selected for calculation. In other cases, such parameters cannot be easily obtained from the parameter table, and then calculation can be performed according to the external dimensions of the magnetic ring, that is, the outer diameter D, the inner diameter d, and the height h of the magnetic ring, through another formula.

[0068] Specifically, the insertion loss refers to the ratio of the voltage at the back end of the insertion point before and after the device under test (DUT) is inserted into a given transmission system, and its unit is usually expressed in dB.

[0069] The standard insertion loss test method is to use a calibrated 50Ω signal source and a 50Ω receiver. The insertion loss can be calculated by the following formula:

[0070]

[0071] In this formula:

[0072] a e : Insertion loss, in decibels (dB);

[0073] V 0 : Open - circuit voltage of the 50Ω signal generator, in volts (V); and

[0074] V 2 : Output - terminal voltage of the filter circuit, in volts (V).

[0075] Furthermore, as Figure 2b shown, it is a schematic diagram of a test device 22 for the magnetic permeability of a magnetic device with a network analyzer according to an embodiment of the present invention. As Figure 2b shown, the embodiment can be a special case of the test device 10 as Figure 1 shown. Therefore, the same parts in the test device 10 and the test device 22 are labeled with the same reference numerals, but the present invention is not limited thereto. In other embodiments of the present invention, the host computer and the fixture in the test device 22 may be different from the embodiment as Figure 1 shown.

[0076] In the test device 22 as Figure 2b shown, the measuring instrument 12 as Figure 1 shown is specifically set as a network analyzer 222. The first port Port1 and the second port Port2 of the network analyzer 222 are respectively connected to both sides of the fixture 11, and the network analyzer 222 is also connected to the host computer 13. The host computer 13 can thus receive the S21 parameter from the network analyzer 222, and then calculate the magnetic permeability using this S21 parameter according to the conversion formula between the S21 parameter and the magnetic permeability for a single - turn coil.

[0077] Exemplarily, in an embodiment of the present invention, the conversion formula between the S21 parameter and the magnetic permeability for a single - turn coil is:

[0078]

[0079] Or:

[0080]

[0081] Where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross - sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and S21 is the S21 parameter.

[0082] Specifically, for the S21 parameter, S represents Scatter, which directly translates to "dispersion" and represents the observation of frequency domain characteristics in a circuit. It should be noted that the S21 parameter and insertion loss are two different parameters for describing filter devices, but they are also highly correlated with each other. Specifically, S21(dB) = -IL(dB), where the S21 parameter and IL insertion loss in dB are exactly opposite in sign.

[0083] When defining the two-port S parameters, the return loss of the first port port1 can be calculated by the following formula:

[0084]

[0085] The closer the S11 value is to 0, the better (the lower, generally -25 to -40 dB). A low S11 value indicates less reflection in the transmission path, and the S11 value is also called the Input Reflection Coefficient.

[0086] On this basis, the S21 parameter represents the insertion loss during the process of the signal being transmitted from the first port port 1 to the second port port2, and can be calculated by the following formula:

[0087]

[0088] The closer the S21 value is to 1 (0 dB), the better, indicating less loss during the transmission process. For example, S21 = -3 dB means that about 40% of the input signal is transmitted to the output.

[0089] The above-mentioned S11 and S21 are the two most commonly used parameters. In addition, there are also S22 and S12, which are defined as follows:

[0090]

[0091]

[0092] S22 is the return loss seen from the second port port2, which has the same meaning as the above-mentioned S11, just with a different port. And S12 represents the insertion loss seen from the second port port2, which is equal to S21.

[0093] Furthermore, in the embodiment as Figure 1 shown, the fixture 11 can have as Figure 3a and3b The structure shown. Specifically, in the embodiments as shown in Figure 3a and 3b collectively, the fixture 11 includes a base 110, a cylinder 111 disposed on the base 110 and for passing through the magnetic ring a, and two connection ends 112 located on the outer surface of the base 110.

[0094] Among them, the base as shown in Figure 3a and 3b can be understood as the overall framework of the fixture 11, and may include the six surfaces of a cube in space, but it does not exclude that one or some of the surfaces provide openings or the like for the placement of the cylinder 112 and the magnetic ring a.

[0095] On the other hand, Figure 3a and Figure 3b the difference of the fixture 11 shown in Figure 3a is that the two structures of the fixture 11 have different placement methods when measuring the magnetic permeability of the magnetic ring a. It can be understood that the structure of the fixture 11 applicable to Figure 3a is a vertical structure. When measuring the magnetic permeability of the magnetic ring a, it can be placed upright on a plane according to the placement method shown in Figure 3a ; while Figure 3b the structure of the fixture 11 shown in Figure 3b is a horizontal structure. When measuring the magnetic permeability of the magnetic ring a, it can be placed horizontally on a plane according to the placement method shown in Figure 3b shown.

[0096] Preferably, for the convenience of wiring, when the fixture 11 as described in Figure 3a is placed upright according to Figure 3a shown, one of the connection ends 112 is disposed on the outer surface of the upper part of the base 110 (i.e., the overall framework of the fixture 11), and the other connection end 112 is disposed on the outer surface of the side of the base 110 (i.e., the overall framework of the fixture 11). Inside the base 110, the two connection ends 112 can be connected by a flexible wire, so that while realizing the vertical placement of the fixture 11 to measure the magnetic permeability of the magnetic ring a, it will not affect the wiring of the fixture 11 with other instruments and equipment.

[0097] Similarly, when the fixture 11 as described in Figure 3b is placed horizontally according to Figure 3b shown, the two connection ends 112 are respectively located on two opposite surfaces of the base 110 (i.e., the overall framework of the fixture 11), and these two surfaces are also the two side surfaces of the base 110 contacted by the cylinder 111, so that the fixture 11 can be wired with other external instruments and equipment to complete the measurement of the magnetic permeability of the magnetic ring a.

[0098] Another aspect of the present invention also provides a method for testing the magnetic permeability of a magnetic device, which can simply and conveniently test the magnetic permeability and reduce the test cost. As Figure 4 shown, it is a schematic flow chart of a method 40 for testing the magnetic permeability of a magnetic device according to an embodiment of the present invention.

[0099] In this application Figure 4 flowcharts are used to illustrate the operations performed by systems according to embodiments of the present application. It should be understood that the operations described above or below do not necessarily have to be executed precisely in order. Instead, various steps can be processed in reverse order or simultaneously. Also, other operations can be added to these processes, or one or more steps can be removed from these processes.

[0100] As Figure 4 shown, a method 40 for testing the magnetic permeability of a magnetic device according to the present invention includes the following steps.

[0101] Step 41 is to clamp the magnetic device, and the magnetic device includes a magnetic ring through which a single-turn coil passes. Step 42 is to measure the insertion loss or S21 parameter of the magnetic device. Step 43 is to calculate the magnetic permeability using the insertion loss according to the conversion formula between the insertion loss and the magnetic permeability for a single-turn coil, or calculate the magnetic permeability using the S21 parameter according to the conversion formula between the S21 parameter and the magnetic permeability for a single-turn coil.

[0102] In some embodiments of the present invention, the conversion formula between the insertion loss and the magnetic permeability for a single-turn coil in the above step 43 is:

[0103]

[0104] Or:

[0105]

[0106] where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and IL is the insertion loss.

[0107] On the other hand, in some embodiments of the present invention, the conversion formula between the S21 parameter and the magnetic permeability for a single-turn coil in the above step 43 is:

[0108]

[0109] Or:

[0110]

[0111] Wherein μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of ​​the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and S21 is the S21 parameter.

[0112] For other details about the method for testing the magnetic permeability of a magnetic device of the present invention, reference may be made to the above description of the device for testing the magnetic permeability of a magnetic device of the present invention, which will not be described in detail here.

[0113] By adopting the above-mentioned magnetic permeability test device and test method of the magnetic device, the insertion loss device or the S21 parameter test means can be used. After the insertion loss or S21 parameter test of the magnetic device is performed through software calculation and parameter extraction, the magnetic permeability-frequency curve can be directly obtained. The test method is very simple and effectively reduces the test cost.

[0114] In particular, some methods of measuring magnetic permeability using multiple windings in the prior art will increase the parasitic capacitance between turns, thereby affecting the formula relationship between magnetic permeability and insertion loss, resulting in inaccurate testing. Especially at high frequencies, the error will be very large. However, the test device and test method for the magnetic permeability of the magnetic device of the present invention are only suitable for a single-turn coil to pass through the magnetic ring, and one turn of wire is kept through the center of the magnetic ring as much as possible, so as to minimize the generation of parasitic capacitance and ensure the accuracy of the test. For example, in some scenarios of measuring magnetic permeability using multiple windings in the prior art, the test frequency band can only reach about 1MHZ, while the test device and measurement method of the present invention can reach 100MHz, with very good measurement results. The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although it is not clearly stated here, those skilled in the art may make various modifications, improvements and corrections to the present application. Such modifications, improvements and corrections are suggested in the present application, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of the present application.

[0115] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0116] Some aspects of the present application may be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above-mentioned hardware or software may all be referred to as "data block", "module", "engine", "unit", "component" or "system". The processor may be one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. In addition, aspects of the present application may be embodied as a computer product located in one or more computer-readable media, which product includes computer-readable program code. For example, the computer-readable media may include, but is not limited to, magnetic storage devices (such as hard disks, floppy disks, magnetic tapes...), optical disks (such as compact disks CD, digital versatile disks DVD...), smart cards, and flash memory devices (such as cards, sticks, key drives...).

[0117] The computer-readable media may include a propagated data signal having computer program code embodied therein, for example, on a baseband or as part of a carrier wave. The propagated signal may take many forms, including electromagnetic, optical, or the like, or any suitable combination thereof. The computer-readable media may be any computer-readable media other than a computer-readable storage media, which can communicate, propagate, or transport a program for use by being connected to an instruction execution system, apparatus, or device. The program code located on the computer-readable media may be propagated through any appropriate medium, including radio, cable, fiber optic cable, radio frequency signal, or similar media, or any combination of the above media.

[0118] Similarly, it should be noted that, in order to simplify the presentation of the disclosure of the present application and thus help the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of the present application, sometimes multiple features are combined into one embodiment, drawing, or description thereof. However, this method of disclosure does not mean that the features required by the subject matter of the present application are more than those recited in the claims. In fact, the features of the embodiments are less than all the features of the single embodiments disclosed above.

[0119] In some embodiments, numbers are used to describe components and the quantity of attributes. It should be understood that such numbers used in the description of embodiments are, in some examples, modified by the modifiers "about", "approximately" or "substantially". Unless otherwise stated, "about", "approximately" or "substantially" indicate that the stated number allows a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may vary according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining the general number of digits. Although the numerical ranges and parameters used in some embodiments of the present application to confirm the breadth of their scope are approximate values, in specific embodiments, such numerical settings are as precise as possible within the feasible range.

[0120] Although the present application has been described with reference to the current specific embodiments, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions can be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications of the above embodiments are within the scope of the spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A test device for the magnetic permeability of a magnetic device, comprising: a fixture for clamping the magnetic device, the magnetic device including a magnetic ring through which a single-turn coil passes; a measuring instrument for measuring the insertion loss or S21 parameter of the magnetic device; and a host computer connected to the measuring instrument for receiving the insertion loss or S21 parameter, using the insertion loss and calculating the magnetic permeability according to the conversion formula between the insertion loss and the magnetic permeability for a single-turn coil, or using the S21 parameter and calculating the magnetic permeability according to the conversion formula between the S21 parameter and the magnetic permeability for a single-turn coil, where the conversion formula between the insertion loss and the magnetic permeability for a single-turn coil is: or: where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and IL is the insertion loss.

2. The device according to claim 1, wherein the conversion formula between the S21 parameter and the magnetic permeability for a single-turn coil is: or: where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and S21 is the S21 parameter.

3. The device according to claim 1, wherein the fixture includes a base, a cylinder provided on the base for passing through the magnetic ring, and a connection end on the outer surface of the base.

4. A test method for the magnetic permeability of a magnetic device, comprising the following steps: clamping the magnetic device, the magnetic device including a magnetic ring through which a single-turn coil passes; measuring the insertion loss or S21 parameter of the magnetic device; and using the insertion loss and calculating the magnetic permeability according to the conversion formula between the insertion loss and the magnetic permeability for a single-turn coil, or using the S21 parameter and calculating the magnetic permeability according to the conversion formula between the S21 parameter and the magnetic permeability for a single-turn coil, where the conversion formula between the insertion loss and the magnetic permeability for a single-turn coil is: or: where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and IL is the insertion loss.

5. The method according to claim 4, wherein the conversion formula between the S21 parameter and the magnetic permeability for a single-turn coil is: or: where μ is the magnetic permeability, le is the effective magnetic path length of the magnetic ring, Ae is the effective cross-sectional area of the magnetic ring, D is the outer diameter of the magnetic ring, d is the inner diameter of the magnetic ring, h is the height of the magnetic ring, f is the frequency of the measurement signal, and S21 is the S21 parameter.

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